concrete5 Environment switch according to host name

app.php

<?php
// /application/bootstrap/app.php
Route::register('/ccm/request_test', function() {
        header("Pragma: no-cache");
        echo '<dl>';
        ?><dt>Application environment:</dt><dd><?php echo ($this->app->environment()) ? $this->app->environment() : 'default'; ?></dd><?php
        $request = \Concrete\Core\Http\Request::getInstance();
        ?><dt>Client IP:</dt><dd><?php echo $request->getClientIp(); ?></dd><?php
        ?><dt>Host:</dt><dd><?php echo $request->getHost(); ?></dd><?php
        ?><dt>Port:</dt><dd><?php echo $request->getPort(); ?></dd><?php
        ?><dt>Scheme:</dt><dd><?php echo $request->getScheme(); ?></dd><?php
        ?><dt>Secure:</dt><dd><?php echo ($request->isSecure()) ? 'true' : 'false'; ?></dd><?php
        ?><dt>Canonical URL:</dt><dd><?php echo \Core::make('url/canonical'); ?></dd><?php
        ?><dt>Get all headers:</dt><dd><pre><?php var_dump($request->headers->all()); ?></pre></dd><?php
        echo '</dl>';
    });

start.php

<?php
use Concrete\Core\Application\Application;
// /application/bootstrap/start.php

/* 
 * ----------------------------------------------------------------------------
 * Instantiate concrete5
 * ----------------------------------------------------------------------------
 */
$app = new Application();

/*
 * ----------------------------------------------------------------------------
 * Detect the environment based on the hostname of the server
 * ----------------------------------------------------------------------------
 */
$app->detectEnvironment(function() {
    $request = \Concrete\Core\Http\Request::getInstance();
    if (($request->getHost() == 'develop.example.com')) {
        return 'develop';
    } else {
        return 'live';
    }
});

return $app;